Saturday 7 January 2012 18.09 EST
First published on Saturday 7 January 2012 18.09 EST

The 2012 London Olympics will go down in history as a giant "missed opportunity" for young Britons unless David Cameron orders an urgent rethink to revive and boost sport in schools, former Labour Olympics minister Tessa Jowell says.

The stark warning from Jowell, a member of the Olympics board and one of the leading champions of the Games, lays bare mounting concern at sport's highest levels that the Olympics will be scarred by a failure to deliver on the promise of a permanent legacy.

Her comments, in an interview with the Observer, will embarrass Cameron ahead of a special Olympics cabinet meeting this week to fine-tune planning for the £9bn Games, which are now just some 200 days away.

Jowell, who helped frame the successful 2005 UK bid around a promise to "inspire a generation", has been central to the cross-party consensus behind the planning of the Games.

However, she felt she had to speak out to try to reverse the coalition's "incomprehensible" decision to "dismantle" the very national programmes for school sport that had been on course to deliver the legacy. Jowell said the decision in 2010 of the education secretary, Michael Gove, to withdraw funding for the programme of schools sports partnerships had "undone eight years of work at a stroke".

The need to build a legacy through school sport was a "classic example", Jowell argued, of where cross-party cooperation had been necessary – but had broken down after the coalition came to power. Jowell said: "The fact is that kids were beginning to build sport into their everyday lives, using sport as a motivator to get them to school on time, to feel proud of being at school where they could discover abilities that they never thought they had."

There was evidence that sport in primary schools had gone into decline with the Olympics approaching, though statistics were difficult to compile because Gove had abolished the survey that monitors sporting activity.

She said the prime minister "needs to understand that a great national opportunity is slipping away every week – and it can, just, be rescued in time for the Games. The failure to continue the progress toward unprecedented levels of participation in sport for children of all ages in state schools risks being one of the great missed opportunities of the 2012 Olympics."

She called on Cameron to order a complete rethink of policy and re-instate or replace the previous national network of local sporting partnerships, which provided specialist teachers to schools, as a matter of urgency.

Between 2003 and 2010, secondary school children playing two hours or more of sport a week rose from 20% to 85% as the partnerships were built.

Cameron now faces pressure from several directions to act to avoid having the Olympics marred by his government's approach to school sport. Last week Baroness Campbell, who heads the Youth Sport Trust and heads UK Sport, the funding agency for elite Olympic sport, called for a long-term agreement to be reached on funding for school sport. if there was to be any chance of delivering a real legacy from the Games.

"My plea is that if you want a legacy, you need to think long-term strategy," Campbell said. "There was a legacy from the last strategy, which was greater participation [in schools]. If you really want to make the School Games a driver you've got to think long term."

Jowell said: "The decision to bid to host the Games was a decision to do something very big and ambitious for young people's lives. So it is simply not good enough for ministers to wring their hands about childhood obesity, low self-esteem, absenteeism and bad discipline, when there is so much evidence to show the extent to which sport can remedy so many ills."

Ministers are putting in place a new national competition, the School Games, that will climax with finals at the Olympic Park in the summer. They say the Games will be the basis for a policy for competitive sport, although funding is not guaranteed beyond 2014-2015. So far only around half of all schools have signed up to take part.